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authorNicholas Piggin <npiggin@gmail.com>2016-11-02 06:57:01 (GMT)
committerMichael Ellerman <mpe@ellerman.id.au>2016-11-12 09:12:42 (GMT)
commitf23ed166f283b1a6f0a1f0b0c889e8df9a10ff85 (patch)
treea3bce7a07f727a1443ca9cd8a20195a9036a510c /arch/powerpc/kernel
parentfb479e44a9e240a23c2d208c2ace23542a47f41c (diff)
downloadlinux-f23ed166f283b1a6f0a1f0b0c889e8df9a10ff85.tar.xz
powerpc/64s: Fix system reset interrupt winkle wakeups
Wakeups from winkle set the low bit of the HSPRG0 register, to distinguish it from other sleep states. This is also the PACA pointer. The system reset exception handler fails to mask this bit away before using this value before using it as the PACA pointer. Fix this by adding a new type of exception prolog macro where we already have the PACA set in r13, and have the system reset vector mask it out. The winkle wakeup handler will store the masked value back into HSPRG0. Fixes: fb479e44a9e2 ("powerpc/64s: relocation, register save fixes for system reset interrupt") Cc: stable@vger.kernel.org # v3.0+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel')
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S11
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 08ba447..1ba82ea 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -116,7 +116,9 @@ EXC_VIRT_NONE(0x4000, 0x4100)
EXC_REAL_BEGIN(system_reset, 0x100, 0x200)
SET_SCRATCH0(r13)
- EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common, EXC_STD,
+ GET_PACA(r13)
+ clrrdi r13,r13,1 /* Last bit of HSPRG0 is set if waking from winkle */
+ EXCEPTION_PROLOG_PSERIES_PACA(PACA_EXGEN, system_reset_common, EXC_STD,
IDLETEST, 0x100)
EXC_REAL_END(system_reset, 0x100, 0x200)
@@ -124,6 +126,9 @@ EXC_VIRT_NONE(0x4100, 0x4200)
#ifdef CONFIG_PPC_P7_NAP
EXC_COMMON_BEGIN(system_reset_idle_common)
+BEGIN_FTR_SECTION
+ GET_PACA(r13) /* Restore HSPRG0 to get the winkle bit in r13 */
+END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
bl pnv_restore_hyp_resource
li r0,PNV_THREAD_RUNNING
@@ -169,7 +174,7 @@ EXC_REAL_BEGIN(machine_check, 0x200, 0x300)
SET_SCRATCH0(r13) /* save r13 */
/*
* Running native on arch 2.06 or later, we may wakeup from winkle
- * inside machine check. If yes, then last bit of HSPGR0 would be set
+ * inside machine check. If yes, then last bit of HSPRG0 would be set
* to 1. Hence clear it unconditionally.
*/
GET_PACA(r13)
@@ -388,7 +393,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early)
/*
* Go back to winkle. Please note that this thread was woken up in
* machine check from winkle and have not restored the per-subcore
- * state. Hence before going back to winkle, set last bit of HSPGR0
+ * state. Hence before going back to winkle, set last bit of HSPRG0
* to 1. This will make sure that if this thread gets woken up
* again at reset vector 0x100 then it will get chance to restore
* the subcore state.